This study will examine the efficacy and toxicity of the combination chemotherapy using thymidine and carboplatin in patients with recurrent malignant glioma. The sensitization effect between thymidine and carboplatin occurs when the two agents are simultaneously present and becomes apparent with thymidine exposure of only a few hours. We are requesting GCRC approval for this protocol because the GCRC is able to provide a unique, professional service to out patients in treatment and monitoring side effects.